dissosway



n m R V 0 m 6 W A No. 6|4,7o5. lamentedl mm2;` 189s.

. c. M. mssoswAv.

SAFETY DEVICE FDR ELEVATORS 0R HDISTS.

(Application led My 4, 1898.\

(No Model.)

WITNESSES:

Patented Nov. 22, |898.

C. M. DSSSWAY. SAFETY DEVICE FUR ELEVATORS 0R HUISTS.

(Application led May 4, 1898.)

3 Sheet-Sheet 2.

(No Model.)

No. 6|4,-7o5. Patented Nov, 22, |898. r c. M. nlssoswAv.

SAFETY DEVICE FOR ELEVATOBS 0H HOISTS.

(Applicgbion led May 4, 1898.) (N0 Model.) 3 Sheets-Sheet 3.

WITNESS'ES: Y mvENToR YH: Nonms PETERS co, PHOTQUTHD.. wAsNxNGroN. n. c.

OROV-ELL M. DISSOSWAY, LOF NEV YORK, N. Y., ASSIGNOR OF ONE-HALF TO JOHN GOODOHILD, GUARDIAN, OF SAME PLACE. l

SAFETYDEVICE FOR ELEVATORS OR HOISTS.

SPECIFICATION forming part of Letters Patent No. 614,705, dated November 22, 1898.

` Application iiled May 4 1898. Serial No. 679,668. (No model.)

To a/ZZ whom, it may concern:

Beit known that I, CROWELL M. DIssos- WAY, a citizen of the United States, residing in the borough of Manhattan, city, county and State of New York, have invented certain new and useful Improvements in Safety Devices for Elevators or Hoists, of which the following is a specification.

This inventionv relates to the class of dero vices employed on or in operative connection with elevators, hoists, and lifts in order to arrest or check the fall of the car should the hoisting-rope or other hoisting means break or give way.

I5 The object of the invention is to provide an automatic stop device which shall come in play only when the car starts to move downward by gravity at a speed in excess of the maximum speed set foi` the car and one which zo shall come into action promptly before the car can acquire much momentum.

The invention consists, essentially and broadly, in a rotating spirally-formed detent or worm-gear which moves up and down with 2 5 the car, either carried up by the car or by other means, as will be hereinafter described,

and which has a limited vertical movement independent of the car, a device which automatically arrests the rotation of said detent when the car starts to move downward at a speed greater than the maximum speed set therefor and by so doing causes the arrested detent to interlock with fixed projections along the elevator-shaft, and means for ro- 3 5 tating said detent normally at the proper speed.

The important distinction between this safety device and those commonly known resides in the independent character of the de- 4o tent andthe frame in which it is mounted, these latter being free to move up and down to a limited extent independently of the elevator-car, whereby the car when it drops suddenly does not carry the detent with it, but

closes down on the detent, as will be hereinof the safety device on a larger scale, 2 being a side elevation, Fig. 3 an elevation from the direction indicated by the arrow z in Fig. 2, and Fig. 4 a horizontal section at 55 line 004 in Figs. 2 and 3. Fig. 5 is a view similar to Fig. 5, showinga slightly-modified construction. Fig. 6 is a view illustrating a construction wherein the safety device is carried up and down independently of the car. Fig. 6o 7 is a plan of the safety device on the saine scale as Figs. 2, 3, 4, and 5.

Referring primarily to Figs. 1, 2, 3, and 4, which show the invention embodiedin the preferred form, A represents in Fig. l an elevator-car suspended by a hoisting-rope a in a shaft, and B B are uprights extending up the respective opposite sides of the shaft.

C O represent in this figure as a whole the two like safety devices carried by the car. 7o These devices are alike, and one of them is illustrated in detail in Figs. 2, 3, and 4. Referring to these figures particularly, b represents a cog-rack fixed to and extending up the upright B, and adjacent to this rack is a series of detent projections c, also fixed to the inner face of the upright B. This series of detent projections will be conveniently made in the form of rack-teeth, and the series will be hereinafter referred to as the de- 8o tent-rack or worm-gear rack-bar c. In Figs. 2 and 3, LX represents a cross-beam of the car A.

Suspended or hung on the beam ax is a frame 1, provided with a guide-jaw 2, which takes into a guide-groove c in the detentrack c, as clearly shown in Fig. 4, and there is also a similar guide-jaw 3, which engages a guide-groove 19X in the cog-rack b. These guiding devices keep the frame l properly 9.o alined with the racks as the frame moves up and down with the car.

Mounted rotatively in the frame 1 is a short horizontal shaft 4, on which is iixed a pinion 5, that gears with the cog-rack b, whereby the movement of the frame up or down rotates said shaft. On the shaft 4 is a bevel gear-Wheel 6, which gears with a similar wheel 7 on an upright shaft 8, rotatively mounted in the frame l. yAs here shown, this shaft 8 loo extends up through a hole in the beam ax on the car.

Mounted rotatively on the shaft 8 and so as to slide longitudinally thereon is a spiral detent or worm -gear 9, which consists, as herein shown, of a hollow barrel with bearings in its end pieces for the shaft 8, a spiral screw-thread or rib 9X, extending about it externally, and a brake-cone 10 on its upper end. This detent 9 rests on a spiral spring 11 about the shaft S, having washers l2 interposed between the respective ends of the spring 11 and the lower end of the spiral detent and the transverse member of the frame 17 on which the spring is supported. Normally the spring 11 presses the detent 9 upward elasticaliy, and in so doing puts a clutch member fixed on the bottom end piece of the detent into engagement with a clutch member on the shaft S, so that the latter carries the detent with it when it rotates. rlhis clutch device may be of any kind; but as herein shown it is composed of a conical male member 13, fixed on the shaft 8 and having teeth or cogs tapered downward toward the lower end of the cone, and a female member 13X, formed by recessing the lower end of the spiral detent and providing it with teeth interiorly arranged to interlock with the teeth on the member 13 when the members are pressed together. The spiral rib or thread JX on the detent 9 engages between the teeth or projections on the detentnack c; but normally the rib does not touch said teeth, as the detent rotates, when the car moves up and down, with just the proper speed to keep the spiral rib out of contact.

1n or on the beam LX of the car is a hollow brake-cone 10X, into which the cone 10 on the spiral detent 0 is adapted to fit under certain circumstances, which will be hereinafter eX plained. These brake-cones 10 and 10 form a friction-clutch, and any suitable form of friction-clutch may be substituted for that herein shown.

In order to .counterbalance wholly or in part the weight of the frame 1 and the various parts mounted in and on it, a lever 14 is fulcrumed at w on the beam ax, the shorter arm of said lever taking under the upper transverse member of the frame, and a weight 15 is hung on the other or longer arm of the lever. This counterweight should suffice to partly balance the weight of the frame and the parts mounted in it.

The operation of the device is as follows: Normally while the carA is running up and down at any speed within the limit fixed, and which cannot be exceeded by the attendant on the car, the detent 9 will merely rotate out of contact with the teeth of the detent-rack c; but if the rope a, by which the car is suspended, should break and the car drop suddenly by gravity the car will drop away from the frame 1. The member 10 of the frictionclutch on or in the beam ax, Fig. 3, will engage with the member 10 on the spiral detent 9, at the same time forcing the latter down until the spiral rib 9X thereon bears upon a tooth or projection of the rack c, at the same time disengaging the members 13 13X of the clutch, which fixes the detent 9 to the shaft 8. The detent 9 cannot now rotate,and the downward movement of the car will necessarily be arrested. This result is due to the fact that when the car starts to descend at a speed greater than the normal there are several forces tending to prevent the safety device from following with the same speed. One of these is inertia, another the engagement of the pinion 5 with the rack 7), and another the counterbalancing device. rlhis latter device, if the normal maximum speed be very slow, will be set to very nearly counterbalance the weight of the frame and its parts; but if the maximum speed be high the approach to a perfect eounterbalance will not be so near. lVhen the car drops suddenly from a broken rope, the fulcrum fw of the lever 1l descends a little, but this does not affect the counter balancing, and when the spiral detent 9 shall have been pressed to a support on the teeth of the detent-rack c the weight of the de tent 9 will have been removed from the lever and the detent disengaged from the pinion 5 and its gearing. The lnember 13 and the cone 10 serve to limit the up and down move- :ments of the detent or wornrgcar 0 on the shaft S.

It is not absolutely essential to the operation of the safety device that the spiral detent 9 shall be disengaged from the shaft S in case of accident. ltmay be splined on said shaft, as seen in Fig. 5, so as to rotate with but slide longitudinally on the latter. In this view the clutch members 13 13X are omitted from the construction and a spline 1G employed. The advantage of the clutch device 13 13 is that at the moment the spiral detent is depressed in case the rope breaks and the ear falls the detent will be wholly disconnected from the pinion 5 and the drivinggearing and all strain on these parts is removed.

Itis not absolutely necessary that the safety device C shall be carried up and down by the car A, although this latter is the preferred construction. It may be carried by a rope and raised and lowered by said rope and a drum, the latter being driven from the same source as the carin order to obtain uniformity in their motion and speed. This construe tion is illustrated somewhat diagammatically in Fig. G, wherein 17 are the hoisting-ropes of the safety devices C, which wind on and unwind from drums 1S, driven from the pulleys over which the hoisting-rope of the car winds. The drums 1S are represented as driven by belts 19 from the sheaves or pulleys 20, Figs. 1 and G, over which the hoisting-rope a is rove. Any means of hoisting the devices C suited to the particular mechanism for raising and lowering the car A may be employed.

It is preferred to employ two safety dcvices, one at each side of the car, but one IOO IOS

IIO

would serve and the invention is not restricted to two. Preferably, also, the clutch device or brake which arrests the rotation of the spiral detent will be a non -positive or friction clutch, but an ordinary positive clutch will serve, or such, for example, as the clutch 13 13X.

It will be understood that any form' of counterbalance for the safety device may be used. The lever and weight device is illustrated somewhat diagrammatically in the drawings. It will be obvious that a cord over a pulley on the beam ax and a weight attached to the cord will serve the purpose.

Having thus described my invention, I claiml. The combination with an elevator-car, means for operating the same and an upright detent-rack in the shaft in which the car travels, of a safety device which travels normally with the car, said safety device comprising a spiral detent rotatable on an upright axis and having a spiral thread loosely engaging the teeth of the detent-rack, means for rotating` said detent at a speed proportioned to the speed of the car, and a clutch, one member of which is carried by said detent and the other, directly over it, carried by the car, whereby when the car starts to descend at a speed greater than the maximum, the sudden descentof the car closes the clutch and arrests the rotation of the detent, substantially as set forth.

2. The combination with an elevator-car, means for operating the same, an upright detentfrack, and an upright cog-rack, both in the shaft in which thev car travels, of a safety device which travels normally with the car, said safety device comprising a frame, an upright shaft therein, a pinion gearing with the cog-rack and mounted in the frame, intermediate gearing between said pinion and upright shaft, whereby the former drives the latter, a spiral detent on the upright shaft, said detent having a thread loosely engaging the teeth of the detent-rack, and a clutch, one member of which is carried by the detent and the other by the car, the latter being directly over the former and adjacent thereto, whereby when the car starts to descend too rapidly the said clutch members engage and arrest the rotation of the detent, substantially as set forth.

3. The combination with an elevator-car, meansy for operating the same, an upright detent-rack in the elevator-shaft, and a cog-rack also in said shaft, of a safety device C, comprising a frame 1, hung on a part of the car,

an upright shaft 8, in the frame, a pinion 5, gearing with the cog-rack and mounted in the frame, gearing between said pinion and the shaft 8, a spiral detent 9, mounted on the shaft 8 and free to move longitudinally thereon, a spring 1l under said detent, the spiral thread of which detent loosely engages the detentrack, a friction clutch or brake, the member l0 of which is carried by the detent and the member 10X, carried by the car and arranged directly over the member 10, and a counterbalance device all arranged to operate, substantially as set forth.

4. The combination with an elevator-car, means for operating the same, an upright detent-rackin the elevator-shaft, and a oog-rack also in said shaft, of a safety device C, comprising a frame 1, hung on a part of the car, an upright shaft 8, in the frame, a pinion 5, gearing with the cog-rack and mounted in the frame, gearing between said pinion and the shaft 8, a spiral detent 9, mounted on the shaft 8 and having a thread loosely engaging the detent-rack, the clutch member 13 on the shaft 8, a clutch member 13 on the detent to engage therewith, a spring 1l under the detent and operating as described, a brake-cone 10, on the detent 9, a corresponding hollow cone l0 011 the car directly above the cone l0 and adjacent thereto, and the counterbalance de vice, all arranged to operate, substantially as set forth.

5. The combination with an elevator-car, means for operating said car and an upright detent-rack adjacent to the path of the car, of a safety device to arrest the sudden descent of the carin case of accident, said device comprising an upright, spiral detent provided with a spiral thread loosely engaging the teeth of the detentrack, said spiral detent, which moves up and down normally with the car, being free to move vertically to a limited eX- tent independently of the car, means for rotating said detent, normally, at a speed proportioned to the speed of the car, and means carried by the car for arresting the rotation of said detent when the car drops suddenly and independently of said detent, substantially as set forth.

In witness whereof I have hereunto signed my name, this 2d day of May, 1898, in the presence of two subscribing witnesses.

CROVELL M. DISSOSVAY.

Vitnesses:

HENRY OoNNE'rT, PETER A. Ross. 

